Definition: A landform that extends above the surrounding terrain in a limited area. A mountain is generally steeper than a hill, but there is no universally accepted standard definition for the height of a mountain or a hill although a mountain usually has an identifiable summit and a local relief of more than 300m.
Definition: A volcano created by geologically excreted liquids and gases, although there are several different processes which may cause such activity. Temperatures are much cooler than igneous processes.
Definition: A desert biome is a terrestrial biome which loses more liquid water by evapotranspiration than is supplied by precipitation and includes communities adapted to these conditions.
Definition: An opening, or rupture, in the Earth's surface or crust, which allows hot, molten rock, ash and gases to escape from deep below the surface.
